Open Vhost failed should return the real error which send from server.

[barryz]

In the latest version of RabbitMQ, I set the max-connections limitation for a vhost. When I opening
several connections that try to connect to RabbitMQ. The client shows an ErrVhost error. However, I expect to receive a similar error where send from server like this:

Exception (530) Reason: "NOT_ALLOWED - access to vhost 'test_vhost' refused for user 'guest': connection limit (2) is reached"

Therefore, I think it is reasonable to return the original error where send from server.

[michaelklishin]

This is a breaking API change and this client is ridiculously conservative about those. However, there is only code path for opening a connection. Let's wait and see what others think.

[streadway]

I've also been bitten by debugging this error. The error API for connection handshake doesn't easily carry the stage of the handshake along with the reason when using package level errors.

There are a few uses of comparing ErrVhost in the wild: https://github.com/search?q=ErrVhost If the error protocol were changed - would you be willing to create PRs to on the repositories affected?

Alternatively, for usability, what do you think about improving the error message to include max-connection possibility and to investigate the server logs for the actual error?

[michaelklishin]

The vast majority of the ErrVhost uses are vendored code. I haven't inspected all 25 pages but looks like there may be a few dozens of projects that would need updating.

[streadway]

Ok, until we upgrade the call-sites, let's include this as a possible reason to the error string of the ErrVhost variable.

[michaelklishin]

Hey folks,

I'm posting this on behalf of the core team.

As you have noticed, this client hasn't seen a lot of activity recently.
Many users are unhappy about that and we fully recognize that it's a popular
library that should be maintained more actively. There are also many community
members who have contributed pull requests and haven't been merged for various reasons.

Because this client has a long tradition of "no breaking public API changes", certain
reasonable changes will likely never be accepted. This is frustrating to those who
have put in their time and effort into trying to improve this library.

We would like to thank @streadway
for developing this client and maintaining it for a decade — that's a remarkable contribution
to the RabbitMQ ecosystem. We this now is a good time to get more contributors
involved.

Team RabbitMQ has adopted a "hard fork" of this client
in order to give the community a place to evolve the API. Several RabbitMQ core team members
will participate but we think it very much should be a community-driven effort.

What do we mean by "hard fork" and what does it mean for you? The entire history of the project
is retained in the new repository but it is not a GitHub fork by design. The license remains the same
2-clause BSD. The contribution process won't change much (except that we hope to review and accept PRs
reasonably quickly).

What does change is that this new fork will accept reasonable breaking API changes according
to Semantic Versioning (or at least our understanding of it). At the moment the API is identical
to that of streadway/amqp but the package name is different. We will begin reviewing PRs
and merging them if they make sense in the upcoming weeks.

If your PR hasn't been accepted or reviewed, you are welcome to re-submit it for rabbitmq/amqp091-go.
RabbitMQ core team members will evaluate the PRs currently open for streadway/amqp as time allows,
and pull those that don't have any conflicts. We cannot promise that every PR would be accepted
but at least we are open to changing the API going forward.

Note that it is a high season for holidays in some parts of the world, so we may be slower
to respond in the next few weeks but otherwise, we are eager to review as many currently open PRs
as practically possible soon.

Thank you for using RabbitMQ and contributing to this client. On behalf of the RabbitMQ core team,
@ChunyiLyu and @michaelklishin.